The 48-hour pause in bombardment announced by Israel to allow civilians to leave southern Lebanon was interrupted within hours of its start yesterday when the Israeli military launched three air strikes at targets near the border.

Israeli troops also pressed on with a ground offensive around the Lebanese villages of Kfar Kila and al-Taiba. A separate ground incursion began yesterday, with infantry troops and armoured vehicles closing in on the village of Aita al-Shaab, the military said. The village is west of Bint Jbeil, the scene of heavy fighting last week.

An Israeli military spokeswoman said the pause in bombing, which began at 2am yesterday, was a "partial suspension".

The first air strike came after an Israeli tank was hit by an anti-tank rocket just across the border from the Israeli town of Metula, injuring three soldiers. A fighter jet later fired on a truck near the Lebanese border with Syria which the military believed was a target. Lebanese sources said the truck had been carrying aid.

In a separate attack an unmanned Israeli drone fired a rocket at a Lebanese military truck, killing one soldier and injuring three, near an army post in Qasmiyeh. The Israeli military expressed regret, saying it had mistakenly suspected a Hizbullah leader was in the car. It added: "The IDF [Israeli Defence Forces] will continue to operate against anyone posing a threat at the citizens of Israel."

Throughout the day Israeli tanks and field guns kept up a barrage of artillery into southern Lebanon. Israeli television showed armoured bulldozers demolishing buildings, described as "Hizbullah positions", near the border and drones could be heard flying over the area.

Israeli politicians said the 48-hour pause was not a truce and would not stop their offensive against Hizbullah. "We cannot agree to an immediate ceasefire in Lebanon because then we will find ourselves in a few months in a similar situation," Amir Peretz, the Israeli defence minister, told the Knesset, Israel's parliament. "The army will expand and deepen its actions against Hizbullah."

Army generals were reportedly angry with the pause, a decision taken with the knowledge of only a handful of the most senior figures in Israel.

In Kfar Kila, barely 500 metres from the Israeli town of Matula - they are divided by a fence standing in a low plain of orange and olive groves - a small group of Israeli soldiers darted from tree to tree as they approached the town's outskirts.

Residents of two neighbouring villages were told they had until this evening to flee before the shelling starts. According to the residents of the Kfar Kila, Hizbullah was holding off the Israeli advance despite heavy shelling.

"This is the second day that they have tried to advance,' said Ismail Hamoud, 53. "They tried to advance with tanks, but as on the previous day the resistance [Hizbullah] hit three of their tanks. That is when they started firing phosphorus."

Asked about reports of using phosphorus, an Israeli military spokesman said: "The IDF use of weapons and ammunition conforms with international law."

Hizbullah appeared to have halted its rocket fire into Israel yesterday, although a small number of mortars hit. Previous days had seen more than 100 rockets fired.

The Israeli military also dismissed claims from Hizbullah that it had hit an Israeli warship with a rocket off the coast.